The tank likely already has more than enough nutrients from the substrate. Fish food itself is also a complete fertilizer
The key here is to reduce the coloration of the water as it reduces light penetration quite significantly. Light is still the most important factor for planted tanks
lazy-bluegill 
completely unrelated but that is one beautiful piece of driftwood– looks like a cliff!
The tank likely already has more than enough nutrients from the substrate. Fish food itself is also a complete fertilizer
The key here is to reduce the coloration of the water as it reduces light penetration quite significantly. Light is still the most important factor for planted tanks